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Image Enhancement I
Image enhancement refers to tasks of sharpening image features, such as
edges, boundaries, or contrast, to make an image more suitable for visual
display and analysis.
The enhancement process increases the dynamic range of the chos

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Color Image Processing
4 Color is a powerful descriptor that often simplifies object identification
and extraction from a scene.
4 In image analysis, the motivation for using color is that the human eye can
discern thousands of color shades and intensit

ECE 520.414/614
Image Processing and Analysis I
Prof. John Goutsias
Homework #1
1. For each of the image processors described below, determine whether the image processor is
(i) linear, and (ii) shift invariant
(a) g ( x , y ) = f ( x , y ) f ( x z , y )

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Image Enhancement II
Histogram Processing
The histogram provides a global description of the appearance of an
image. It is a graph of the distribution of gray level values within an image.
The histogram p( rk ) , k = 0,1,., L 1, is a discrete function

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Properties of the Fourier Transform of a
Discrete Image
Linearity
The Fourier transform is linear in the sense that
Fcfw_af (m,n)+bg (m,n)=aFcfw_f (m,n)+bFcfw_g (m,n)
Conjugate Symmetry
If f ( m, n ) is a real-valued image, then its Fourier transform ex

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Image Enhancement III
Enhancement by Spatial Filtering
Image enhancement can be achieved by means of a discrete image
processor T() , in which case the enhanced image g will be given by
g ( m, n ) = T( f )( m, n )
The processor may be linear or nonlin

THE HUMAN VISUAL SYSTEM
An objective of image processing and analysis is to develop techniques to
help a human observer interpret the content of an image. For this reason,
understanding human visual perception is important.
The human visual system is, b

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IMAGE QUANTIZATION
This is the step subsequent to sampling in image digitization.
A quantizer maps a continuous variable u into a discrete variable ud ,
which takes values in a finite set
cfw_r1, r2 , rL
of numbers.
Define cfw_t k , k = 1,2,., L + 1

INTRODUCTION
Image Processing and Analysis
Concerned with the manipulation and analysis of pictures by
computers.
Improvement of pictorial information for human interpretation.
Processing of scene data for autonomous machine perception.
Important Tasks

The Continuous Image Processor
f (x,y )
T()
g (x , y )
A two-dimensional continuous image processor is considered to be a
transformation T() of an input two-dimensional continuous image
f ( x , y ) to an output two-dimensional continuous image g( x, y).